DUP MLA Stephen Moutray says he has asked party officers not to consider him as a candidate for the next Assembly elections.
The Upper Bann representative, who has represented the constituency since 2007, says he will leave the Assembly to pursue business interests and give more time to his family.
The Lurgan man’s announcement ends weeks of speculation about who will run for the DUP in Upper Bann next May.
Councillor Carla Lockhart was recently selected by party members as one of two candidates and Mr Moutray’s future was immediately cast into doubt.
Sydney Anderson, whose base is in the Portadown half of the constituency, will run alongside Ms Lockhart.
Mr Moutray said: “It has been a privilege to serve the people of Upper Bann in the Northern Ireland Assembly since 2007.
“Over the last number of months I have been involved in a number of new projects within my business and following discussions with my family and with party colleagues I have decided to leave the Assembly at the end of this mandate in order to pursue my business interests as well as dedicate more time to family life.
“I have conveyed my decision to the Party Officers and asked them not to consider me as a potential candidate during the ongoing selection process for the Upper Bann constituency. The party knows that I will continue to be active in the party at a local constituency level in the forthcoming election campaign and will continue to serve the party in a part - time capacity in whatever opportunities may arise.
“I want to take this opportunity to thank all those who have voted for me and had me returned successfully on 3 occasions. It has been both a privilege and humbling experience for which I am truly thankful.”